src/or/proto_control0.c

   1 /* Copyright (c) 2001 Matej Pfajfar.
   2  * Copyright (c) 2001-2004, Roger Dingledine.
   3  * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
   4  * Copyright (c) 2007-2017, The Tor Project, Inc. */
   5 /* See LICENSE for licensing information */
   6
   7 #include "or.h"
   8 #include "buffers.h"
   9 #include "proto_control0.h"
  10
  11 /** Return 1 iff buf looks more like it has an (obsolete) v0 controller
  12  * command on it than any valid v1 controller command. */
  13 int
  14 peek_buf_has_control0_command(buf_t *buf)
  15 {
  16   if (buf_datalen(buf) >= 4) {
  17     char header[4];
  18     uint16_t cmd;
  19     buf_peek(buf, header, sizeof(header));
  20     cmd = ntohs(get_uint16(header+2));
  21     if (cmd <= 0x14)
  22       return 1; /* This is definitely not a v1 control command. */
  23   }
  24   return 0;
  25 }
  26